A. Field of the Invention
The present invention relates generally to deformable three-dimensional puzzles and, particularly to three dimensional puzzles having the shape of a regular hexahedral prism.
B. Description of the Prior Art
Most of the three-dimensional puzzles known until now belong to the group of so called Rubic type puzzles the first of which was the Rubic cube which became also the most popular one. The high symmetry of these puzzles which enables their suitable design nevertheless, from the mathematical point of view, contributes to their rather easy solution.
A quite different group of puzzles, taken again from the mathematical point of view, represent puzzles which are capable of changing their symmetry in various configurations. They are also different with respect to their design since their various configurations may be diversified not only by way of the color permutations of segment faces but also through their various shapes and symmetries.
To this new type of puzzles belongs the cube disclosed in the Czechoslovak patent on the industrial design No. 15666. The construction of the internal mechanism and arrangement of the exterior segments of this puzzle allow, however, only those compact shape configurations which are characterized by arrangement of the principal faces of the exterior segments belonging to the middle structure in one plane when these exterior segments engage each other with their entire contact surfaces. As far as the exterior segments are not turned to this position the exterior segments of the puzzle do not occupy a stable position.
In these unstable interim positions the outside functional faces of the exterior segments do not engage each other and on the contrary the non-functional lateral faces of the exterior segments are exposed. Thus, in those interim positions the puzzle does not take up geometrically interesting shapes and does not constitute a stable compact body.
The said three-dimensional body may become stable in shape only in the positions when the outside form of the body is in vertical direction defined by two horizontal planes. The overall visual impression of the puzzle is characterized only by those dominant integral faces of the exterior segments belonging to the outside structures.